US6328475B1 - Air bearing, in particular for the shaft of a motor spindle - Google Patents

Air bearing, in particular for the shaft of a motor spindle Download PDF

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Publication number
US6328475B1
US6328475B1 US09/508,673 US50867300A US6328475B1 US 6328475 B1 US6328475 B1 US 6328475B1 US 50867300 A US50867300 A US 50867300A US 6328475 B1 US6328475 B1 US 6328475B1
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United States
Prior art keywords
bearing
air
mating
shaft
bearing surface
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Expired - Lifetime
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US09/508,673
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English (en)
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Alfred Jäger
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Alfred Jaeger GmbH
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Individual
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Assigned to ALFRED JAGER GMBH reassignment ALFRED JAGER GMBH ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: JAGER, ALFRED
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C33/00—Parts of bearings; Special methods for making bearings or parts thereof
    • F16C33/02—Parts of sliding-contact bearings
    • F16C33/04—Brasses; Bushes; Linings
    • F16C33/16—Sliding surface consisting mainly of graphite
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C32/00—Bearings not otherwise provided for
    • F16C32/06—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings
    • F16C32/0603—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings supported by a gas cushion, e.g. an air cushion
    • F16C32/0614—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings supported by a gas cushion, e.g. an air cushion the gas being supplied under pressure, e.g. aerostatic bearings
    • F16C32/0622—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings supported by a gas cushion, e.g. an air cushion the gas being supplied under pressure, e.g. aerostatic bearings via nozzles, restrictors
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C32/00—Bearings not otherwise provided for
    • F16C32/06—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings
    • F16C32/0681—Construction or mounting aspects of hydrostatic bearings, for exclusively rotary movement, related to the direction of load
    • F16C32/0696—Construction or mounting aspects of hydrostatic bearings, for exclusively rotary movement, related to the direction of load for both radial and axial load
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C2322/00—Apparatus used in shaping articles
    • F16C2322/39—General build up of machine tools, e.g. spindles, slides, actuators
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S384/00—Bearings
    • Y10S384/90—Cooling or heating
    • Y10S384/912—Metallic

Definitions

  • This invention relates to an air bearing for a rotor adapted to rotate at (high peripheral speed, in particular for the shaft of a motor spindle for driving a machining tool, with provision being made for an air gap between a bearing surface of the rotor and a mating bearing surface of a stationary bearing element, said mating bearing surface having several bearing pockets communicating via bores in the bearing element with a source of compressed air.
  • Air bearings of the type referred to are known from DE 21 24 918 A1. They are used primarily for supporting shafts rotating at very high rotational frequency and accordingly high peripheral speed in order to be able to cope with the frictional resistance of the bearing and the resultant heat development in the bearing. With air bearings of this type, the rotor is supported by air cushions that are produced with the aid of air supplied under pressure to the air gap between the bearing surface and the mating bearing surface and which prevent contact between the bearing surface and the mating bearing surface. Contactless bearing of the rotor is guaranteed not only while it is rotating but also when it is stationary. Air bearings are highly sensitive to overloading during operation, i.e., with the rotator rotating at high speed.
  • the materials suitable for manufacturing air-lubricated plain bearings are metals, ceramic materials and plastics.
  • the use of stainless steels to counter the risk of corrosion is considered possible, but these materials are said as a rule to have poor sliding properties.
  • a ceramic material regarded to have good antifrictional and machining properties is metal-impregnated sintered carbon, a porous sintered graphite impregnated with metals such as white metal, lead bronze, antimony or silver.
  • an aerostatically supported roller designed for high speeds and low loads, being comprised of a sleeve made of resin-impregnated carbon graphite.
  • the sleeve is supported on an inner sleeve made of porous carbon graphite, which is carried by a hub provided with channels for the supply of compressed gas.
  • the compressed gas directed through the porous inner sleeve produces a gas film which carries the rotary outer sleeve and centers it relative to the inner sleeve.
  • the sleeve slides on the inner sleeve, with the antifrictional properties observed as this occurred having been good.
  • this object is accomplished in that the rotor is made of a corrosion-resistant steel alloy having hardened bearing surfaces while the bearing element with the mating bearing surface is made of a densely compacted, air-impervious graphite material.
  • the mating of materials as disclosed in the present invention is suitable in particular measure for air bearings, acted upon from outside, of shafts rotating at very high peripheral speed such as are used on motor spindles for the machining of workpieces.
  • the antifriction conditions needing to be satisfied in such applications are characterized primarily by a very high energy density because in the start-up and run-out phase the shaft is aerostatically supported, and failure of the air film by overloading of the bearing generally occurs at full shaft speed.
  • a further significant advantage of the bearing configuration of the present invention resides in that the bearing can be renewed with little effort if it is damaged by overly frequent or excessively long overloading. And because there is no seizing of the bearing, a damaged bearing can be dismantled without difficulty. As a rule, the bearing surface of the rotor turns out to be undamaged or the damage is slight enough to rectify by lapping.
  • FIG. 1 is a cross sectional view of an air bearing for the shaft of a motor spindle
  • FIG. 2 is a detail view, on an enlarged scale, of a bearing element with a bearing pocket.
  • the drawing shows an air bearing 1 for the radial and axial bearing of the shaft 2 of a high-speed frequency-controlled motor spindle for driving a machining tool.
  • the shaft 2 has a cylindrical bearing surface 3 and an annular collar 4 with two parallel, circular-ring shaped bearing surfaces 5 , 6 facing away from each other.
  • a housing 7 surrounding the shaft 2 receives therein a sleeve-shaped bearing element 8 with a hollow cylindrical mating bearing surface 9 for radial bearing purposes and, on either side of the annular collar 4 , annular-disk shaped bearing elements 10 with mating bearing surfaces 11 facing each other and lying in radial planes for axial bearing purposes.
  • bearing pockets 13 are provided in the mating bearing surface 9 of the bearing element 8 arranged along two spaced circumferential lines so as to be equally spaced apart circumferentially.
  • equidistant bearing pockets 13 are arranged in the mating bearing surfaces 11 of the bearing elements 10 on the arc of a circle.
  • the bearing pockets 13 are connected via throttle bores 14 to supply bores 15 which are supplied with compressed air via annular grooves 16 in the housing 7 .
  • annular chambers 17 communicating with atmosphere either directly or via relief bores 18 are provided adjacent to the mating bearing surfaces 9 , 11 .
  • the shaft 2 and the integrally molded annular collar 4 are made of stainless steel.
  • the bearing surfaces 3 , 5 , 6 are hardened and manufactured to the highest geometrical accuracy and precision-lapped surfaces.
  • the bearing elements 8 , 10 are air-tight electrographite compacts with an inorganic phosphate content of over 3%, e.g., FE 65 or FE 45Y2 electrographite from the company Schunk GmbH in 35452 Heuchelheim, Germany.
  • the mating bearing surfaces 9 , 11 exhibit the same geometrical accuracy and surface quality as the bearing surfaces 3 , 5 , 6 .
  • the bearing gap between the bearing surfaces and the mating bearing surfaces lies in the range of 0.01 to 0.02 mm.
  • air cushions are produced by air supplied under pressure between the bearing surfaces 3 , 5 , 6 and the mating bearing surfaces 9 , 11 in the area of the bearing pockets, thereby centering the bearing surfaces 3 , 5 , 6 of the shaft 2 between the mating bearing surfaces 9 , 11 of the bearing elements 8 , 10 and preventing contact being made between the bearing surfaces and the mating bearing surfaces.
  • the continuously supplied air escapes through the bearing gap into the annular chambers 17 , thus achieving the necessary cooling even at high peripheral speeds of 10,000 ms ⁇ 1 and more.

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Magnetic Bearings And Hydrostatic Bearings (AREA)
US09/508,673 1998-05-08 1999-08-03 Air bearing, in particular for the shaft of a motor spindle Expired - Lifetime US6328475B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE19835339A DE19835339A1 (de) 1998-08-05 1998-08-05 Luftlager, insbesondere für die Welle einer Motorspindel
DE19835339 1998-08-05
PCT/DE1999/002360 WO2000008345A1 (de) 1998-08-05 1999-08-03 Luftlager, insbesondere für die welle einer motorspindel

Publications (1)

Publication Number Publication Date
US6328475B1 true US6328475B1 (en) 2001-12-11

Family

ID=7876525

Family Applications (1)

Application Number Title Priority Date Filing Date
US09/508,673 Expired - Lifetime US6328475B1 (en) 1998-05-08 1999-08-03 Air bearing, in particular for the shaft of a motor spindle

Country Status (5)

Country Link
US (1) US6328475B1 (de)
EP (1) EP1021660B1 (de)
DE (2) DE19835339A1 (de)
ES (1) ES2221755T3 (de)
WO (1) WO2000008345A1 (de)

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040109622A1 (en) * 2002-04-11 2004-06-10 Yoshio Fujikawa Externally pressurized gas bearing and spindle equipment using this
US20040136114A1 (en) * 2002-07-23 2004-07-15 Toffle Mark A. Servo track writer with helium bearing
US7136262B2 (en) * 2002-08-21 2006-11-14 Minebea Co. Ltd Pivot assembly preloaded by laser welding for hard disk drive use
US20060283227A1 (en) * 2005-06-20 2006-12-21 Monahan Joseph J Rolling mill roller guide
US20080187266A1 (en) * 2007-02-02 2008-08-07 Takanobu Akiyama Roll machining apparatus
US20120064814A1 (en) * 2010-09-15 2012-03-15 Beers Craig M Shaft for air bearing and motor cooling in compressor
US8517665B2 (en) 2010-12-21 2013-08-27 Hamilton Sundstrand Corporation Thrust bearing shaft for thrust and journal air bearing cooling in an air machine
US8529192B2 (en) 2010-09-15 2013-09-10 Hamilton Sundstrand Corporation Thrust bearing shaft for thrust and journal air bearing cooling in a compressor
US8734017B1 (en) 2013-03-08 2014-05-27 Hamilton Sundstrand Corporation Air bearing shaft
US20140374506A1 (en) * 2014-09-08 2014-12-25 Gunnar van der Steur Composite air bearing assembly
US9970481B1 (en) 2017-09-29 2018-05-15 Efc Systems, Inc. Rotary coating atomizer having vibration damping air bearings
CN111305912A (zh) * 2020-02-26 2020-06-19 华电电力科学研究院有限公司 一种利用气浮轴承平衡轴向力的单级径向透平发电系统
US11136667B2 (en) * 2007-01-08 2021-10-05 Eastman Kodak Company Deposition system and method using a delivery head separated from a substrate by gas pressure

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE20311890U1 (de) * 2003-08-01 2004-12-09 Deublin Gmbh Drehdurchführung für Minimalmengenschmierung
CN107269702A (zh) * 2017-07-20 2017-10-20 中国工程物理研究院机械制造工艺研究所 一种静压气体径向轴承

Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE255373C (de)
US3645590A (en) 1970-12-17 1972-02-29 Gen Motors Corp Carbon-graphite gas-bearing roll
DE2124918A1 (de) 1970-05-20 1972-08-24 Compagnie Industrielle Des Telecommunications Cit-Alcatel, Paris Hochpräzisionsspindel mit aerostatischem Lager-Drucklager
US4982126A (en) 1988-04-29 1991-01-01 Societe De Mecanique Magnetique S.A. Auxiliary bearing having a graphite stator for a rotary shaft mounted on magnetic bearings
US5017022A (en) 1988-11-09 1991-05-21 Allied-Signal, Inc. High temperature bearing
EP0471329A2 (de) 1990-08-16 1992-02-19 Schunk Kohlenstofftechnik GmbH Verwendung von imprägniertem Elektrographit als Gleitkörper in Form von Drehschiebern und Gleitringen
CH683844A5 (fr) 1990-10-04 1994-05-31 Suisse Electronique Microtech Combinaison autolubrifiante de revêtements.
EP0606970A1 (de) 1993-01-11 1994-07-20 DOW CORNING GmbH Feste Schmiermittelzusammensetzung
JPH06213236A (ja) 1992-11-26 1994-08-02 Canon Inc 気体軸受
JPH08105443A (ja) 1994-10-04 1996-04-23 Nippon Carbon Co Ltd 不浸透性黒鉛材料を用いた静圧空気軸受
US5692840A (en) 1996-12-12 1997-12-02 Phase Metrics Crash tolerant air bearing spindle
US5998898A (en) * 1997-12-19 1999-12-07 Matsushita Electric Industrial Co., Ltd. Motor having hydrodynamic bearing

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3645500A (en) 1970-08-21 1972-02-29 Black & Decker Mfg Co Throttle sleeve for fluid-powered device
DD255373A1 (de) * 1986-12-23 1988-03-30 Akad Wissenschaften Ddr Aerostatisches luftlager

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE255373C (de)
DE2124918A1 (de) 1970-05-20 1972-08-24 Compagnie Industrielle Des Telecommunications Cit-Alcatel, Paris Hochpräzisionsspindel mit aerostatischem Lager-Drucklager
US3645590A (en) 1970-12-17 1972-02-29 Gen Motors Corp Carbon-graphite gas-bearing roll
US4982126A (en) 1988-04-29 1991-01-01 Societe De Mecanique Magnetique S.A. Auxiliary bearing having a graphite stator for a rotary shaft mounted on magnetic bearings
US5017022A (en) 1988-11-09 1991-05-21 Allied-Signal, Inc. High temperature bearing
EP0471329A2 (de) 1990-08-16 1992-02-19 Schunk Kohlenstofftechnik GmbH Verwendung von imprägniertem Elektrographit als Gleitkörper in Form von Drehschiebern und Gleitringen
CH683844A5 (fr) 1990-10-04 1994-05-31 Suisse Electronique Microtech Combinaison autolubrifiante de revêtements.
JPH06213236A (ja) 1992-11-26 1994-08-02 Canon Inc 気体軸受
EP0606970A1 (de) 1993-01-11 1994-07-20 DOW CORNING GmbH Feste Schmiermittelzusammensetzung
JPH08105443A (ja) 1994-10-04 1996-04-23 Nippon Carbon Co Ltd 不浸透性黒鉛材料を用いた静圧空気軸受
US5692840A (en) 1996-12-12 1997-12-02 Phase Metrics Crash tolerant air bearing spindle
US5998898A (en) * 1997-12-19 1999-12-07 Matsushita Electric Industrial Co., Ltd. Motor having hydrodynamic bearing

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
Patent Abstracts of Japan, vol. 18, No. 583, Nov. 8, 1994 & JP 06-213236 (Canon), Aug. 2, 1994.
Patent Abstracts of Japan, vol. 1996, No. 8, Aug. 30, 1996 & JP 08-105443 (Nippon Carbon), Apr. 23, 1996.
W. J. Bartz et al, Luftlagerungen, Expert Verlag, 1982, ISBN 3-8169-0992-2, pp. 22 and 99.

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7066652B2 (en) * 2002-04-11 2006-06-27 Ntn Corporation Externally pressurized gas bearing and spindle equipment using this
US20040109622A1 (en) * 2002-04-11 2004-06-10 Yoshio Fujikawa Externally pressurized gas bearing and spindle equipment using this
US20080158728A1 (en) * 2002-07-23 2008-07-03 Seagate Technology Llc Writer with helium bearing
US20040136114A1 (en) * 2002-07-23 2004-07-15 Toffle Mark A. Servo track writer with helium bearing
US9236083B2 (en) 2002-07-23 2016-01-12 Seagate Technology, Llc Writer with working fluid bearing
US7345844B2 (en) 2002-07-23 2008-03-18 Seagate Technology Llc Servo track writer with helium bearing
US7136262B2 (en) * 2002-08-21 2006-11-14 Minebea Co. Ltd Pivot assembly preloaded by laser welding for hard disk drive use
US20060283227A1 (en) * 2005-06-20 2006-12-21 Monahan Joseph J Rolling mill roller guide
US11136667B2 (en) * 2007-01-08 2021-10-05 Eastman Kodak Company Deposition system and method using a delivery head separated from a substrate by gas pressure
US20080187266A1 (en) * 2007-02-02 2008-08-07 Takanobu Akiyama Roll machining apparatus
US8256963B2 (en) * 2007-02-02 2012-09-04 Toshiba Kikai Kabushiki Kaisha Roll machining apparatus
US20120064814A1 (en) * 2010-09-15 2012-03-15 Beers Craig M Shaft for air bearing and motor cooling in compressor
US8529192B2 (en) 2010-09-15 2013-09-10 Hamilton Sundstrand Corporation Thrust bearing shaft for thrust and journal air bearing cooling in a compressor
US8622620B2 (en) * 2010-09-15 2014-01-07 Hamilton Sundstrand Corporation Shaft for air bearing and motor cooling in compressor
US8517665B2 (en) 2010-12-21 2013-08-27 Hamilton Sundstrand Corporation Thrust bearing shaft for thrust and journal air bearing cooling in an air machine
US8734017B1 (en) 2013-03-08 2014-05-27 Hamilton Sundstrand Corporation Air bearing shaft
US8973848B2 (en) * 2014-09-08 2015-03-10 Efc Systems, Inc. Composite air bearing assembly
US20140374506A1 (en) * 2014-09-08 2014-12-25 Gunnar van der Steur Composite air bearing assembly
US9970481B1 (en) 2017-09-29 2018-05-15 Efc Systems, Inc. Rotary coating atomizer having vibration damping air bearings
CN111305912A (zh) * 2020-02-26 2020-06-19 华电电力科学研究院有限公司 一种利用气浮轴承平衡轴向力的单级径向透平发电系统

Also Published As

Publication number Publication date
WO2000008345A1 (de) 2000-02-17
DE59909743D1 (de) 2004-07-22
DE19835339A1 (de) 2000-02-17
EP1021660B1 (de) 2004-06-16
ES2221755T3 (es) 2005-01-01
EP1021660A1 (de) 2000-07-26

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